1. Field of the Invention
The present invention relates to a computer joystick, more particularly, to a computer joystick having two optical sensors for generating vector signals to indicate the current position of the joystick's handle.
2. Description of the Prior Art
Computer joysticks are usually used as two-dimensional pointing control systems which use a rotatable joystick handle to continuously generate two-dimensional vector signals each represents a current position of the joystick handle. The vector signals generated by a joystick are different from the displacement signals generated by a mouse which indicate the amount and direction of each displacement of the mouse instead of a position of the mouse.
A conventional computer joystick usually comprises a housing, a joystick handle rotatably installed in the housing for driving two rotatable shafts inside the housing, two position detectors made by variable resistors to detect tilted angles of the two shafts, and a control circuit connected to the two position detectors for generating vector signals to indicate the tilted angles of the two shafts which indicate the current position of the joystick handle. One major drawback of the conventional computer joystick is that the two variable resistors can easily be damaged by frequent or forceful use of the joystick handle. Inaccurate measurements of the tilted positions of tie two shafts may be reported by the two variable resistors when they are damaged by the frictional forces exerted insides the variable resistors.